Make register ST channel set for correct Hybrid/VMM pair.

Before this, Any caput to AllST-S record would only set channels values to
hybrid 0, vmm 0 because of hardcoded values.

This commit makes the vmmST_ an array with epics parameters.
The function getPair discovers the HYBRID-VMM pair for the parameter
that was called and sets the correct pair register's values.

Also, records are loaded with .sub files so we don't need to keep repeating
record names with different numbers.

All have been tested and works.